Sheet iron piling



Feb. 25, 1936. o. WOLFF SHEET IRON FILING Filed Aug. 25, 1934 Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE Application August 25, 1934, Serial No. 741,501 In Germany September 7, 1933 1 Claim.

My invention relates to an improvement of the manufacture and of the shape and of the properties of sheet steel pilings.

For economic reasons rolling is the only manufacturing process to be used for steel pilings.

There are two possibilities to obtain a perfect fastening between the pilings: to produce, if possible by rolling, a special interlocking iron or to shape the edges of the pilings in such a manner, that they interlock with each other.

The second possibility is preferable for economic reasons, but hitherto no satisfactory means of rolling is found out. For on the one side the interlocking of the edges of aforesaid pilings necessitates an accumulation of matter just in the edges not easily obtainable by rolling, and on the other side, the desired shape of the edges requires underlappings in the profile of the piling.

For this reason a much employed profile for pilings, which interlock at their edges without the use of a special lock iron (Larssen pilings) is ,manufactured by rolling as follows: up to the last but one pass a normal design is used, but before the last pass guiding devices are arranged, to efiect a spiral torsion by means of which the lock is bent and introduced into the rolls where the piling gets its final shape.

These known steel sheet pilings have a uniform shape at both side edges of each piling. The edge is thickened and bent twice.

My present invention starts from this known shape of piling, but avoids some of its disadvantages. When both edges of the piling are of uniform shape, a real clutching does not take place, the interlocking being simply obtained through the contigui'ty of the thickened edges. Therefore the mutual guiding action of the piling edges during the ramming is not satisfactory and particularly with heavy building ground difficulties frequently arise. My present invention aims to avoid same by thickening the piling edges only on one side, whereas the other side is reduced to an exactly analogous shape. By this formation is reached, that the twopiling edges interlock like clutches, but that their manufacture is at least just as simple as with the aforesaid known piling. To form the one edge without thickening is even much simpler.

The drawing herewith illustrates an example of my invention namely:

Figure 1 is a View of the interlock.

Figure 2 is a view of two C shaped pilings and Figure 3 shows the last two passes of the rolling mill, A being the finishing pass and B the last but one.

In Figure l the piling edge a has the known shape of a conical thickening, extending to the end of the piling.

In the second, nearly rectangular bend of this edge, the outer surface b does not run parallel with the inner surface of the piling as is the case with the known piling, but it runs parallel to the opposite surface of the thickened part a. By this means is reached, that the piling edge d of the contiguous piling is guided on both sides by the surfaces b and c'. This edge d of the contiguous piling, (not thickened) shows, as a further important feature of my invention, a swelling e behind the second nearly rectangular bend, the one side surface I of which runs parallel with the adjoining side surface of the thickening 0,. Thus this thickening a is likewise guided twice between 11" and e.

As is shown by Figure 3 this kind of sheet piling may be manufactured into the final shape by simple rolling without any guides and profiles.

To insert this piling into the rolling mill any 20 normal device suitable for I and U-irons may be used.

To produce the thickened edge a by bending it in the last pass, is easier in the simple rolling process as with the known piling, because the reinforcement of the profile at the place of the first fiexure, caused by the inclination of the surface b gives a better guidance to the iron, when this is bent finally. The manufacture of the other edge of the piling is made much simpler, because the outer end d of the edge is not more projecting and the thickening e means only a small accumulation of material at a place nearer to the centre of the piling.

A comparison with known pilings of similar construction has shown, that the interlock after my invention is thrice as strong.

Having thus described my invention, what I claim is:

A steel piling comprising two members having their marginal edges turned back to present oppositely arranged hook-shaped formations in interlocked engagement with each other, the outer piling edge of one portion being inclined inwardly and provided with parallel inner and outer side faces, a thickened portion on the same member opposite the said piling edge and provided with an inclined surface cooperating with the inner side face of the outer piling edge to form a substantially wedge-shaped recess, the outer piling edge of the other marginal edge portion being enlarged into a wedge-shaped form for snugly engaging the wedge-shaped recess, said enlarged wedge-shaped portion cooperating with the member of which it forms a part to provide a parallel sided recess which snugly receives the first-mentioned piling edge.

O'I'I'O WOLFF. 

